One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,17)(12,14)(13,16)(15,19)(18,24)(20,22)(21,23)(25,26,32,31)(27,33,39,38)(28,37,29,34)(30,36,40,35)(1,2)(3,5)(4,6)(7,8)(9,11,14,19)(10,15,12,17)(13,18,22,21)(16,23,20,24)(25,27,32,39)(26,33,31,38)(28,36,29,35)(30,37,40,34)(1,2,4,6)(3,5,7,8)(10,12)(15,17)(16,20)(23,24)(25,28,32,29)(26,34,31,37)(27,35,39,36)(30,33,40,38)(3,7)(5,8)(9,11)(10,15)(12,17)(13,21)(14,19)(16,24)(18,22)(20,23)(25,29,32,28)(26,34,31,37)(27,36,39,35)(30,33,40,38)(1,2)(3,5)(4,6)(7,8)(9,12,14,10)(11,17,19,15)(13,20,22,16)(18,24,21,23)(25,30,32,40)(26,35,31,36)(27,37,39,34)(28,38,29,33)(1,3)(2,5)(4,7)(6,8)(9,13)(10,16)(11,18)(12,20)(14,22)(15,23)(17,24)(19,21)(25,31,32,26)(27,38,39,33)(28,37,29,34)(30,36,40,35)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.